Hitherto, various studies have been made on pharmacological activities of thienopyrimidine compounds as disclosed in, for examle, U.S. Pat. Nos. 3,272,811, 3,318,881 and 3,318,883, and British Pat. No. 1,048,986, etc. However, the pharmacology of thiopyranopyrimidine compound has not been studied extensively in the art.
As a result of studies on the synthesis and the utility of novel thiopyranopyrimidine derivatives, the present inventors found that the thiopyranopyrimidine compounds represented by the formula (I) and the pharmaceutically acceptable acid addition salts thereof exhibit excellent hypoglycemic activity, platelet aggregation inhibitory activity, anti-histamine and anti-allergy activity.